This invention relates to a special support, or "jack", to be attached to the frame of a trailer or other land vehicle. The invention is intended especially for a detachable trailer towed by a motor vehicle. One example of such a detachable trailer is a boat hauling trailer with a forwardly extending tongue, for hitching to a towing vehicle and wheels disposed to the rear for travel. A recurring problem encountered with such trailers when unattended or when detached from the towing vehicle is theft or unintended movement. Various systems have been devised as anti-theft measures for such detachable trailers but all such previous measures have generally been expensive, complex in construction, deployment and operation, and frequently unreliable.
It is known to provide supporting devices to supplement the wheels for such trailers which are deployable when the trailer is at rest. However, previous devices have been designed solely for the purpose of increased stability for the trailer at rest. Furthermore, prior art devices have required extensive time and effort to deploy.